<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * A null KeyCache that does not cache at all.
 *
 * @package    Swift
 * @subpackage KeyCache
 * @author     Chris Corbyn
 */
class Swift_KeyCache_NullKeyCache implements Swift_KeyCache
{
	/**
	 * Set a string into the cache under $itemKey for the namespace $nsKey.
	 *
	 * @see MODE_WRITE, MODE_APPEND
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 * @param string $string
	 * @param integer $mode
	 */
	public function setString($nsKey, $itemKey, $string, $mode)
	{
	}

	/**
	 * Set a ByteStream into the cache under $itemKey for the namespace $nsKey.
	 *
	 * @see MODE_WRITE, MODE_APPEND
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 * @param Swift_OutputByteStream $os
	 * @param integer $mode
	 */
	public function importFromByteStream($nsKey, $itemKey, Swift_OutputByteStream $os, $mode)
	{
	}

	/**
	 * Provides a ByteStream which when written to, writes data to $itemKey.
	 *
	 * NOTE: The stream will always write in append mode.
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 * @param Swift_InputByteStream $writeThrough
	 *
	 * @return Swift_InputByteStream
	 */
	public function getInputByteStream($nsKey, $itemKey, Swift_InputByteStream $writeThrough = null)
	{
	}

	/**
	 * Get data back out of the cache as a string.
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 *
	 * @return string
	 */
	public function getString($nsKey, $itemKey)
	{
	}

	/**
	 * Get data back out of the cache as a ByteStream.
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 * @param Swift_InputByteStream $is to write the data to
	 */
	public function exportToByteStream($nsKey, $itemKey, Swift_InputByteStream $is)
	{
	}

	/**
	 * Check if the given $itemKey exists in the namespace $nsKey.
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 *
	 * @return boolean
	 */
	public function hasKey($nsKey, $itemKey)
	{
		return false;
	}

	/**
	 * Clear data for $itemKey in the namespace $nsKey if it exists.
	 *
	 * @param string $nsKey
	 * @param string $itemKey
	 */
	public function clearKey($nsKey, $itemKey)
	{
	}

	/**
	 * Clear all data in the namespace $nsKey if it exists.
	 *
	 * @param string $nsKey
	 */
	public function clearAll($nsKey)
	{
	}
}
